The invention relates to toys of the type including interconnectable chain links. It has been proposed heretofore to form such chain links so that the playing child can learn to build certain types of apparatus, for example to connect a drive sprocket by a chain with a driven sprocket; or to convey material in toy buckets attached to chain links; or to attach treads to chain links for building toy full-track vehicles and the like.
For assembling such buckets or treads or other toy elements to the chain links it is desirable to facilitate the attaching of the toy elements and also to insure proper mutual orientation of the elements when they are interconnected. In this latter aspect, difficulties have been encountered in the past.